Salmonellosis is an insidious and potentially epidemic problem in pre-weaned dairy
calves. Managing this disease, or any other diarrheal disease, is a financial burden to
producers. Calf mortalities and medicinal treatments are overt costs of salmonellosis,
while hidden costs include hampered weight gains and persistent intestinal colonization
of the pathogen. In this study, we examined the anti-Salmonella effects of Saccharomyces
cerevisiae fermentation products (SCFP) incorporated into both the milk replacer and the
starter grain. In a blinded study, 2–8 day-old calves were fed SCFP (n = 20 calves) or an
SCFP-free Control (n = 20 calves) for two weeks before and three weeks after experimental
challenge with Salmonella enterica serotype Typhimurium. Following the challenge, calves
were monitored for clinical signs and parameters associated with salmonellosis. Calves
were then euthanized and examined for rumen development and intestinal Salmonella
colonization. When compared to calves that received milk replacer and feed lacking SCFP,
calves fed SCFP had fewer bouts of diarrhea and fever. Rumens from these calves were
more developed, as measured by the length of papillae, which is consistent with the
enhanced weight gain observed in this treatment group. Additionally, Salmonella intestinal
colonization was reduced in SCFP-fed calves and Salmonella fecal shedding disappeared at
an earlier stage in these calves. This study revealed that the combination of two
proprietary S. cerevisiae fermentation products provide marked benefit for preventing the
negative effects of salmonellosis in pre-weaned dairy calves, while also boosting
productivity. The mechanism of action needs to be clarified, but it may be related to the
observed decrease in colonization by the pathogen and increase in rumen development.